Apparatus and method of acquiring and storing data of close contacts

ABSTRACT

A method of recording close contacts for disease control, the method including the steps of using a device to transmit identity and date/time of contact details to a similar device for each close contact. Identity details of the similar device are received and store for at least predetermined time for each close contact. At the expiry of the predetermined time the received identity details may be overwritten if the memory is full. The stored identity details are used to determine identities of persons with whom close contact had been made within the predetermined time. The device has embedded therein a semiconductor processor device, a memory device, a clock and a transmitter/receiver with an antenna.

CROSS-REFERENCE TO OTHER APPLICATIONS

This is a National Phase of International Application No.PCT/SG2003/000182, filed on Jul. 31, 2003, which claims priority fromSingaporean Patent Application No. 200302514-5, filed on May 6, 2003.

FIELD OF THE INVENTION

This invention relates to a method and apparatus for acquiring andstoring data of close contacts and refers particularly, though notexclusively, to a device with transmitting and receiving functions, andmemory, and to a method for acquiring and storing data of close contactsfor disease control.

BACKGROUND TO THE INVENTION

Many infectious diseases require relatively close contact for thedisease to be transmitted. For example, Severe Acute RespiratorySyndrome (“SARS”) is spread through droplets of phlegm from a sneeze orcough. This requires two persons to be reasonably close—within a fewmeters of each other—for disease transmission.

When a patient is suspected of having a contagious disease requiringclose contact for transmission, all those with whom the patient has comeinto close contact since contracting the disease need to be found todetermine if they have also contracted the disease. This is presentlyconducted by circulating notices, and asking the patient. As the patientmay by that stage be quite ill, this ability to recall all closecontacts over several days is quite limited. If the patient is elderly,or a child, it will be severally limited. Unintentional close contactcan also occur in places such as, for example, a lift where the patientwill not know the identity of the persons with whom the lift was shared,or when a person uses a lift that was used by an infected patient withina transmission time of the disease.

SUMMARY OF THE INVENTION

According to one aspect, there is provided a device for use in recordingclose contact for disease tracking, the device having embedded thereinat least one circuit including:

-   (a) a semiconductor processor device;-   (b) a memory device;-   (c) a clock;-   (d) an identity number; and-   (e) a transmitter/receiver with an antenna.

Two or more of the semiconductor processor device, the memory device,the clock and the transmitter/receiver may be integral or separate.

Each item of received data is stamped with a date and time the data wasreceived. The data together with its date and time of receipt may bestored in the memory device for at least a predetermined period of time,the predetermined time being not less than an incubation period of thedisease. Preferably, the memory device uses a first-in-first-out logic.Data will preferably not be overwritten until the memory is full. If thestored data contains an entry for a received identity, and the sameidentity is later recorded, the new date and time stamp may be added tothe data already recorded for that identity. If the data is downloadedfor processing, the data downloaded may be overwritten. Alternatively,the downloaded data may be deleted from the memory.

The received data may comprise identity details of similar devices thathave come into close contact with the device. Close contact may be adistance not greater than the transmitting range of the device, and thedistance may be not less than a transmission range of the disease. Theduration of the close contact may be determined and stored.

The device may have a built-in battery for providing power to thecircuit. It may also have a built-in low battery warning that may beeither or both of audio and visual.

In another aspect, there is provided a method of recording closecontacts for disease control, the method including the steps:

-   (a) using a device to transmit identity details to at least one    other similar device when the device and the at least one other    device come into close contact;-   (b) receiving from the at least one other similar device identity    details of the at least one other similar device;-   (c) recording the date of receipt and time of receipt of the    received identity details;-   (d) storing in a memory of the device the received identity details,    date of receipt and time of receipt; and-   (e) downloading and using the stored identity details to determine    identities of persons with whom close contact had been made.

Preferably, the memory uses a first-in-first-out logic. After the devicehas been used for a number of days, the memory will be full and it willstay full. When the memory is full and a new identity detail isreceived, the new identity detail will be date and time stamped, and thenew identity detail with its date and time stamp will overwrite theoldest identity, with its date and time stamp, in the memory.

The device may have embedded therein at least one circuit including:

-   (a) a semiconductor processor device;-   (b) a memory device;-   (c) a clock;-   (d) the identity; and-   (e) a transmitter/receiver with an antenna.

The device may also have a battery for providing power to the circuit.

Close contact may be a distance not less than a transmission range ofthe disease. The device may have a transmission range not less than thetransmission range of the disease.

The duration of the close contact may also be determined and stored. Theduration of the close contact may be the time the device and the atleast one other device are in transmission range. The duration may bedetermined by recording the start of the close contact and the end ofthe close contact, and determining the difference. The duration may bein system clock counts or real time.

The device may be issued to a person on a temporary basis for theduration of a stay of the person in a controlled environment the devicebeing tracked by reference to the identity of the person.

The controlled environment may be one or more of: a hospital, aneducational institution, an office building, and a military base. Thetracking may be by reference to an identifier of the person or alocation. The identifier of the person may be one or more of identitycard number, passport number, social security number, and, employmentpass number. If by location it may be by one or more of building,annexe, floor number, a room number, and a lift number.

The controlled environment may have at least one reader for downloadingthe stored identity, and date, time and duration details. Thedownloading may be by wireless transmission.

A penultimate aspect provides a device for use in performing the methoddescribed above.

In a final aspect there is provided a software arrangement that isoperable on a processor, comprising a software arrangement computerprogram code that configures the processor to perform one or morefunctions as described above.

DESCRIPTION OF THE DRAWINGS

In order that the invention may be readily understood and put intopractical effect, there shall now be described by way of non-limitativeexample only preferred embodiments of the present invention, thedescription being with reference to the accompanying illustrativedrawings, in which:

FIG. 1 is a schematic view of a preferred form of device according toone aspect of the present invention;

FIG. 2 is an illustration of a close contact situation; and

FIG. 3 is a flow chart of a preferred method according to another aspectof the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

To first refer to FIG. 1, there is shown a preferred form of device 10.The device 10 may be an identity device, security device, or othersimilar device, worn or carried by a user. The device 10 has embedded init a semiconductor processor device 12 that is powered by a battery 16.A suitable transmitter/receiver 13 with an antenna 14 is used to passdata to semiconductor processor device 12, and to send data fromsemiconductor processor device 12.

A semiconductor memory device 18 is also provided to store data receivedby semiconductor processor device 12. A reference clock 15 is used sothat each received identity will be tagged with the date and time ofreceipt Semiconductor memory 18 may be a separate semiconductor device(as shown) or may be integral with semiconductor processor device 12.The memory 18 may include temporary memory and permanent memory. Thememory 18 preferably uses a first-in-first-out logic. The clock 15 maybe integral with semiconductor processor 12, or may be separate.

To refer to FIGS. 2 and 3, the process is illustrated. Here the device10 is being worn by a first user 8. As the semiconductor 12 is poweredby battery 16, it constantly sends a signal 20 querying if there are anydevices similar to device 10 within close proximity. The signal (and allother transmissions/receptions) is a radio frequency signal ofrelatively low strength so it has a useful range of a few meters only.The signal strength may be adjustable according to the particularrequirements. The range may be, for example, two or three meters. Therange is preferably matched to the closeness of proximity required forthe disease being tracked so that the transmission range of device 10 isnot less than the transmission range of the disease. In the case of SARSthe transmission range of the disease is two or three meters. If thedisease needs physical contact, the disease transmission range may beless than two meters. If the disease has a transmission range of four orfive meters, the transmission range of device 10 is preferably at leastfive meters.

Until another device 6 worn by a second user 4 is within transmissionrange of device 10, device 10 is in a start or standby mode 20. Whenanother device 6, worn by the second user 4, and similar to device 10,is within the transmission range of device 10, the device 6 will receivethe query signal at 22, and will initiate a handshake procedure at 26 bysending a response to device 10. This is detected by device 10 at 24,and the handshake procedure 26 follows. The handshake procedure 26 maybe required to ensure that when there are more than two devices 10, 6 inclose contact with each other, each of the devices 10, 6 will be able tosend its identity to each other device in a controlled manner, and willreceive the identity of each other device in a coordinated manner.Therefore, when more than two devices are together, all the devices willbe able to exchange and store the identity of each other device.

Upon completion of the handshake procedure 26, device 10 sends at 28 itsidentity details to the device 6, and the device 6 sends its identitydetails to device 10. The identity details of device 10 are received bydevice 6 at step 30, and processed by its semiconductor device 12. Thefirst part of the process is for device 10 to determine at 32 of it haspreviously come into close contact with device 6, and if the details ofdevice 6 are in the memory 18 of device 10. If not, at 34 the device 10determines if its temporary memory is full. If it is, in 36 it writesthe oldest record in the temporary memory to the permanent memory tothus free some of temporary memory. The oldest record in the temporarymemory is then overwritten with the new data in step 38, and device 10reverts back to the start 20. The date and time stamps are stored withthe identity details. The duration of the close contact may also bedetermined. This may be by determining when contact is discontinued andrecording the difference between “start contact” and “end contact”, ineither real time or system clock counts.

If the result in step 32 is yes, the duration count is increased in step42. In step 44, the system determines if the duration count is at amaximum. If not, in 50 it reverts back to the start 20; but if it is thedata is written to the permanent memory in 46, and in 48 reverts back tostart 22.

If in step 34 the temporary memory is not full, the data is written tothe temporary memory in step 52; and in step 54 the process reverts backto the start 22.

As each disease has a known incubation period, any symptoms of thedisease should be revealed within a predetermined time. Thepredetermined time should not be less than the known incubation period.Therefore, data relating to any close contact needs to be retained forat least the predetermined time. In the case of SARS, for example, thenormal incubation period is ten days. Allowing for possible variationsdue to individual physiology, extent of exposure, and so forth, thepredetermined time should be a little longer than the known incubationperiod. For an incubation period of ten days (SARS), the predeterminedtime should be about fourteen days.

If the earlier close contact recorded in the memory is very recent, itmay discard the new identity as well as its date and time stamp andduration. By very recent it is meant to cover situations where the samepeople are working together continuously in relatively close contact forextended periods such as, for example, medical staff in an operatingroom. By avoiding repeated entries, battery power and memory may besaved.

A time limit may be applied such that if the memory (both permanent andtemporary) is full yet the oldest data recorded is less than thepredetermined time, the device will stop recording data and provide awarning to the wearer that a download is required to free memory formore data. The warning may be linked to a low battery level warning.Additionally or alternatively, if the contents of memory 18 aredownloaded and saved in a separate data management system/computer, anydownloaded data may be overwritten.

If person 8 shows symptoms of the disease being tracked, their device 10can be obtained and all data stored in memory 18 can be downloaded. Byusing a lookup table of device identifiers and the person to whom thedevice had been issued, all persons who had been in close contact withperson 8, over at least the predetermined time, can be obtained. Thosepersons can then be contacted. Downloading may erase data stored inmemory 18, or may that data to be overwritten.

In a controlled environment such as, for example, a hospital,educational institution, military base, office building, and so forth,it is possible to ensure that all persons who enter the environment areissued with a device 10. For permanent staff, the device 10 may be, orbe part of, their normal identity/security/pass device. Casual workersor visitors may be issued a device 10 on a temporary basis with thedevice issued being tracked according to the identity of the person,time and date. Tracking may also be by location.

The identity of the person may be linked using an identity device suchas, for example, identity card number, passport number, social securitynumber, employment pass number, or the like. Preferably, the identitydevice, passport, or the like has a machine-readable device such as, forexample, a bar code to facilitate speedy processing.

If tracking by location, it may be by one or more of building, annexe,floor number, a room number, a corridor number, and a lift number.Therefore, if a location such as, for example, a lift, building, annexe,floor, corridor, or room is installed with a device so that when aperson with a similar device enters the location, the device willexchange identity with the similar device. This enables the tracking ofpersons by location to be able to determine problems due tocontamination of the air or a surface in the location.

The controlled environment may have proximity readers for automaticallyreading and downloading all data from the memory whenever the device 10is in close proximity to the reader. The proximity reader may be in anarea where staff gather and will be relatively stationary for asufficient time. This may be, for example, bathrooms, toilets, staffcanteens, security entries and exists, and so forth. The proximityreader may be integrated with a re-charger for battery 16. This isuseful if the full memory warning described above uses a warning linkedto low battery level so the user will immediately recharge their devicebattery, thus also downloading all data recorded in the memory.

If data is downloaded from the memory 18, it may be tagged as being ableto be overwritten even if the predetermined time has not yet expired.

Whilst there has been described in the foregoing description preferredembodiments of the present invention, it will be understood by thoseskilled in the technology that many variations or modifications indetails of design, construction or operation may be made withoutdeparting from the present invention.

The present invention extends to all features disclosed, both individualand in all possible permutations and combinations.

1. A device for use in recording incidence and duration of close contactfor tracking at least one disease, the device having embedded therein atleast one circuit including: a semiconductor processor; a memory; aclock; an identifier; and a transmitter/receiver with an antenna,wherein the transmitter/receiver is for receiving the identifier of atleast one other similar device when the device and the at least oneother similar device are in close contact, the semiconductor processorbeing for stamping the received identifier with a received date and areceived time, and the memory being for storing the received identifierwith its received date and time, and wherein the received identifier andits received date and time are stored in the memory for a predeterminedtime of not less than an incubation time for the at least one disease.2. A device as claimed in claim 1, wherein at least two selected fromthe group consisting of: the semiconductor processor, the memory, theclock and the transmitter/receiver, are integral.
 3. A device as claimedin claim 1, wherein the memory device uses a first-in-first-out logic.4. A device as claimed in claim 1, wherein the duration is determined byrecording a start time of the close contact and an end time of the closecontact, and determining a difference.
 5. A device as claimed in claim1, wherein the duration is in one of system clock counts, and real time.6. A device as claimed in claim 1, wherein the received identifier, itsreceived date and time stamp, and the duration are able to beoverwritten when the predetermined time has expired and the memorydevice is full.
 7. A device as claimed in claim 6, wherein when data inthe memory device is downloaded, the data is able to be overwritten by anewly received identifier, its received date and time, and its duration,or is able to be deleted.
 8. A device as claimed in claim 1, whereinclose contact is a distance not greater than a transmitting range of thedevice.
 9. A device as claimed in claim 8, wherein the distance is notless than the transmission range of the disease.
 10. A device as claimedin claim 1, wherein there is further included a battery to provide powerto the at least one circuit.
 11. A device as claimed in claim 1, whereinthe memory comprises a temporary memory and a permanent memory.
 12. Adevice as claimed in claim 11, wherein data is first written to thetemporary memory, and data is only written to the permanent memory whenthe temporary memory is full.
 13. A device as claimed in claim 12,wherein oldest data in the temporary memory is first written to thepermanent memory before the oldest data is overwritten.
 14. A device asclaimed in claim 1, wherein the device comprises at least a part of anitem selected from the group consisting of: an identity device, asecurity pass, and a pass card.
 15. A method of recording incidence andduration of close contacts for disease control, the method including:(a) using a device to transmit identity details of the device to atleast one other similar device when the device and the at least oneother similar device are in close contact; (b) receiving from the atleast one other similar device and identifier of the at least one othersimilar device; (c) processing the received identifier by adding to it adate and time of receipt; (d) storing in a memory the receivedidentifier together with its date and time of receipt until the memoryis full, whereupon it is able to be overwritten by a newly receivedidentifier together with its date and time of receipt; and (e)downloading and using the stored received identifiers together withtheir date and time of receipt to determine identities of persons withwhom close contact had been made, wherein the received identifier andits date and time of receipt are stored in the memory for at least apredetermined time, the predetermined time being not less than anincubation time for the disease.
 16. A method as claimed in claim 15,wherein the device has embedded therein at least one circuit including:a semiconductor processor device; the memory; a clock; atransmitter/receiver and an antenna; and the identity.
 17. A method asclaimed in claim 15, wherein the memory uses a first-in-first-out logic.18. A method as claimed in claim 15, wherein close contact is a distancenot less than a transmission range of the disease.
 19. A method asclaimed in claim 18, wherein the device has transmission range not lessthan the transmission range of the disease.
 20. A method as claimed inclaim 15, wherein the device comprises at least a part of an itemselected from the group consisting of: an identity device, a securitypass, and a pass card.
 21. A method as claimed in claim 15, wherein thedevice is issued to a person on a temporary basis for the duration of astay of the person in a controlled environment, the device being trackedby reference to an identity of the person, time and date.
 22. A methodas claimed in claim 20, wherein the device is also tracked by referenceto a location.
 23. A method as claimed in claim 22, wherein the locationis one or more selected from the group consisting of: building, annexe,floor number, a room number, a corridor number, and a lift number.
 24. Amethod as claimed in claim 21, wherein the controlled environment is oneor more selected from the group consisting of: a hospital, aneducational institution, an office building, and a military base.
 25. Amethod as claimed in claim 21, wherein the tracking is by reference toan identifier of the person, the identifier being one or more selectedfrom the group consisting of: identity card number, passport number,social security number, and employment pass number.
 26. A method asclaimed in claim 21, wherein the controlled environment has at least onereader for downloading the stored identifiers and their date and time ofreceipt.
 27. A method as claimed in claim 26, wherein the at least onereader is associated with a battery charger for the device.
 28. A methodas claimed in claim 15, wherein the duration of close contact is a timethe device and the at least one other similar device are in transmissionrange.
 29. A method as claimed in claim 15, wherein the duration isdetermined by recording a start of the close contact and an end of theclose contact, and determining the difference.
 30. A method as claimedin claim 15, wherein the duration is in one of system clock counts andreal time.
 31. A method as claimed in claim 15, wherein if a personshows symptoms of the disease, all identifiers and their date and timeof receipt stored in the memory of the device of that person isdownloaded and a lookup table of device identifiers and the persons towhom the device had been issued is used to determine all persons who hadbeen in close contact with the person over at least the predeterminedtime.
 32. A method as claimed in claim 15, wherein prior to step (a)there is performed a preliminary procedure when the at least one othersimilar device is within a transmission range of the device, the atleast one other similar device will receive a query signal from thedevice and will initiate a handshake procedure to ensure that when thereare more than one at least one other similar devices in close contactwith the device, each of the devices and the at least one other similardevices will be able to send its identity to each other in a controlledmanner, and will receive the identity of each other in a co-ordinatedmanner.
 33. A method as claimed in claim 15, wherein between processsteps (b) and (c) the received identifiers stored in memory are firstchecked to determine if the received identity has been stored within thepredetermined time and, if yes, the new date and time stamp are added todata already recorded in the memory for that identity.
 34. A method asclaimed in claim 33, where if the earlier close contact recorded in thememory is very recent, the new identity as well as its date and timestamp, and duration, is discarded.
 35. A method as claimed in claim 29,wherein if the memory is full yet the oldest data recorded is less thanthe predetermined time, the device will stop recording data and providea warning to the wearer that a download is required to free memory formore data.
 36. A method as claimed in claim 35, wherein the warning islinked to a low battery level warning.
 37. A method as claimed in claim15, wherein the memory comprises a temporary memory and a permanentmemory.
 38. A method as claimed in claim 37, wherein data is firstwritten to the temporary memory, and data is only written to thepermanent memory when the temporary memory is full.
 39. A method asclaimed in claim 38, wherein oldest data in the temporary memory isfirst written to the permanent memory before the oldest data isoverwritten.
 40. A method as claimed in claim 31, wherein downloading isby wireless transmission.
 41. A device for use in performing the methodof claim
 15. 42. A software arrangement that is operable on a processor,the software arrangement comprising a computer program code thatconfigures the processor to perform one or more functions as claimed inclaim 15.